Researchers with the National Bureau of Economic Research have reviewed 55 separate studies regarding climate change and human violence and come to the conclusion that there is a “meaningful connection” between the two, ThinkProgress reported.

Scientists looked at conflicts between individual people – “domestic violence, road rage, assault, murder, and rape” – as well as between larger groups – “riots, ethnic violence, land invasions, gang violence, civil war and other forms of political instability, such as coups.” They found that rising temperatures and drastic changes in rainfall patterns have a real link to increases in both individual and large-group violence. Researchers wrote,

“We find that deviations from moderate temperatures and precipitation patterns systematically increase the risk of conflict, often substantially, with average effects that are highly statistically significant.”

As ThinkProgress pointed out, this study “doesn’t confirm exactly what is going on; there could still be a correlation-versus-causation problem between climate change and violence, for example.”

Marshall Burke, one of the authors of the report and a researcher at Stanford, told the Washington Post that “for a degree Celsius of temperature increase (1.8 degrees Fahrenheit) … there could be a 20 percent increase in civil conflict in Africa,” and in the US each degree increase should bring “a one percent increase in interpersonal conflicts.”

This report echoes what the Pentagon said in it’s own report released earlier this week, calling climate change an “immediate threat.” Department of Defense Secretary Chuck Hagel said at a conference in Peru, “Destruction and devastation will from hurricanes can sow the seeds for instability. Droughts and crop failures can leave millions of people without any lifeline and trigger waves of mass migration.”